More Kentuckians, particularly older children and teens, should get a booster vaccine to prevent the onset of pertussis, a highly contagious disease more commonly known as whooping cough, the Kentucky Department for Public Health (DPH) announced today.

Though there are relatively few whooping cough cases in the state each year, public health surveillance has detected an increase in recent months. Health officials suspect the spike could be attributed to waning immunity to pertussis vaccination, which typically occurs around age 10 in those vaccinated in infancy and early childhood.

“We strongly encourage those who haven’t done so to get an adolescent or adult pertussis booster vaccine,” said William Hacker, M.D., DPH commissioner. “Often, people don’t realize that vaccines can wear off over a period of time. This can lead to an increase in diseases like whooping cough, a debilitating and prolonged illness.”

Since October, more than 60 whooping cough cases have been reported throughout Kentucky. The highest concentration of cases has occurred in Bullitt, Franklin and Hardin counties.This follows a trend observed nationwide. According to the Centers for Disease Control and Prevention, 5,000-7,000 cases are reported in the United States each year, and the incidence has increased steadily since the 1980s.

“It’s extremely important for communities to work together to control the spread of the disease,” said Kraig Humbaugh, M.D., state epidemiologist for DPH. “Developing community-wide immunity through vaccination is an important strategy for pertussis control.”

Caused by the bacteria Bordetella pertussis, whooping cough is contracted by breathing in contaminated respiratory droplets or contact with articles freshly contaminated with contaminated droplets.

Early symptoms of pertussis include runny nose, sneezing, mild cough and low-grade fever. After one to two weeks, long cough spells develop. The illness can last up to 10 weeks.

Pertussis can be dangerous, especially for young children and infants, who can develop breathing problems (apnea), pneumonia, seizures and brain damage. Pertussis can also cause death (rarely), especially in very young infants. Some individuals are at high risk for acquiring severe disease following exposure to pertussis. Those individuals include infants younger than 1 year, and people with certain immunodeficiency conditions, or other underlying medical conditions such as chronic lung disease, respiratory insufficiency or cystic fibrosis. Adults and adolescents are often the reservoirs of pertussis in a community, even though children are more likely to be tested and diagnosed.

Whooping cough, which is highly contagious, can create tremendous burdens for communities, resulting in missed work and school days, numerous doctor visits and sometimes hospitalization.

Infants get their first dose of pertussis vaccine, in combination with diphtheria and tetanus (DTaP), at 2 months, 4 months and 6 months of age. Boosters are given at 12 to 15 months and then around age 4 or 5. People ages 10 to 64 can get a pertussis booster.